Twisted in Time

When Marisol tries to prove that magic doesn't exist, she somehow manages to do the exact opposite.

"No," I argued. "I've tried so many times to reason with you. It doesn't work. So I'm going to show you that there's nothing to be afraid of."
I flipped to a random page of the ancient text and attempted to read whatever off the wall language it was written in. As I read, a strange warm feeling filled my body. I knew it felt good to be right, but it couldn't feel that good could it? I was nearly at the bottom of the page when the book was ripped from my hands and a scream echoed through the room.
The space became engulfed in blinding light and made seeing all but impossible. The warm feeling inside me started to grow hotter and hotter until I felt like I was going to explode. The heat was unbearable for what seemed like forever, but it wasn't nearly as bad as what came after. When I was able to open my eyes, the first thing I noticed was...a horse?